Pad adapted for the curing of concrete roads and similar purposes



March 17, 1936. H, LEV|NE 2,033,989

PAD ADAPTED FOR THE CURING OF CONCRETE ROADS AND SIMILAR PURPOSES FiledApril 26, 1935 INVEI IT 'OR.

BY M.

ATTORNEY;

Patented Mar. 17, 1936 UNITED STATES PATENT OFFICE PAD ADAPTED FOR THECURING OF CON CRETE ROADS AND SIMILAR PURPOSES My invention relates topads adapted for the.

curing, or ageing, of composition and aggregate deposits and refersparticularly to pads adapted for the curing, or ageing, 'of depositssuitable for the production of roads, walks, foundations and similarpurposes.

My pad is particularly advantageous in the building of composition andaggregate deposits,

as for instance concrete, for road constructions and I will referspecifically to such constructions, but not limiting my inventionthereto.

In the building of a composition concrete road, the concrete is laiddown upon and spread over a suitable foundation material in a wetcondition and it must be allowed to cure, or age, under such conditionsas will cause an eflective binding between the materials of thecomposition.

Experience has shown that if the concrete is allowed to dry too rapidly,the surface is dried before the interior of the mass, resulting in anuneven binding of .the materials of the composition thus producing anuneven, and ineffective material for tramc purposes which is liable tocrack and disintegrate.

It is, therefore, necessary to control the rapidity of the evaporationof the water in the concrete mass in such a manner that it will occurupwardly from the interior of the mass, the surface being the last toharden.

The usual practice followed to accomplish this desired result is tocover the surface of the newly laid concrete with burlap, hay orv strawand to pour. water over this covering from time to time, thus keepingthe concrete face in a moistened condition and allowing of the upwardevaporation of the water in the mass.

As the covering materials now employed are non-absorbent or onlyslightly absorbent of water, the greater portion of the applied waterruns through the covering and away from the concrete surface and ishence ineffective for the desired result.-

In practice it has been found that this covering must have water poured,or sprinkled, upon it every two or three hours for a period of aboutseven days, and as water is frequently difficult to obtain along theroadway, this process is expensive and is uneconomic as to both time andexpense.

My invention overcomes the above mentioned, and other, objectionablefeatures of the present employed methods and presents means whereby more1 effective and uniform results can be obtained with less water andin agreatly reduced period of time.

I have found that if the surface of the freshly laid concrete be coveredwith a water-saturated web of loosely matted water-absorbent material,

the evaporation of the water of the concrete mass will take place evenlyover its entire surfaces, and hence evenly throughout the mass, and thata satisfactory result can usually be obtained within a period ofseventy-two hours.

I have further found that usually the water contained in the saturatedweb is suflicient to accomplish the desired result, although additionalwater may be applied if required.

I have further found that unfelted materials are moreeffectivethanfelted materials because of their more porous nature, thus allowingfreer evaporation resulting in more rapid curing and I have furtherfound that cotton fibers in a matted condition are particularly suitablefor the production of uniform curing in a minimum period of time.

As my device is in the form of a web, or pad, it can be readily andquickly laid upon the surface of the concrete, it overcomes thedifflc'ulty incident to the spreading of hay and straw, and as it can beeasily removed as a unit construc tion, there are no loose materialsrequiring collection and removal.

Further as my device can be employed for repeated operations it presentsa very considerable saving in money investment.

My invention consists in the employment of a web, or pad, of looselymatted fibrous waterabsorbent material, such as cotton, wool etc., ofsufflcient strength to permit considerable or sustained handling, and ifnecessary, it may be covered by attached layers of an easily waterpermeable fabric which will allow of the unimpeded evaporation of watertherethrough.

I prefer that these outer layers be of net-like construction of jute,cotton, wool or other suitable threads. I

My web may be of any width and length, but it is of course advisable tomake it of the size of the standard road dimensions. I

In employing the pad of my invention, I prefer to pass my web, or pad,through a trough of water so as to thoroughly soak it and then spread itupon the freshly laid concrete and experience has shown thatthe amountof water thus. absorbed is usually sufiicient for the proper evaporationof the water in the concrete mass and that further water need not beapplied.

The dry web or pad, may be spread upon the.

concrete mass and water sprinkled thereover, but the same uniformity ofwater absorption can not be thus obtained as is scribed method.

When the water has evaporated from my device and the concrete mass, mydevice is rolled, preferably on a wooden rod, passedv through a troughof water and applied upon a new surface of concrete.

In the accompanying drawing illustrating one form of a pad of myinvention, similar parts are designated by similar numerals.

Figure 1 is a top -plan view of one form of the pad of my invention.

Figure 2 is a section through the line 2-4 of Figure, 1.

Figure 3 is a top plan view of the pad placed upon a concrete-cementdeposit, broken away for clearness of description.

The pad shown in the accompanying drawing consists of a sheet, web, orpad, of loosely matted cotton III, which is enclosed in an upper andlower net-like material formed by the jute threads "-4 I. The jutenettings are attached to each other and to the cotton pad by means ofstitchings H-ll.

In Figure 3 showing the application of the pad of Figures 1 and 2, thedeposit'mass consists of a concrete bed l2, covered by a cement layerIS. The web pad III, I I is spread upon the freshly laid possible by thefirst deconcrete cement deposit as shown and the combination-allowed todry by evaporation, or the dry pad is spread upon the deposit and thenmoistened and allowed to dry by evaporation.

Among the other advantages possessed by the employment of my depositfrom the influence of the sun and weather, the prevention of the depositfrom sudden changes of temperature, of the deposit through the mattedmaterial.

Experiments have shown that because of the properties of the materialsemployed in my process, and particularly because of the uniform pad arethe protection ofthe and the gradual cooling moisture content of thedeposit during curing the fiexual strength of the finished product isvery considerably increased.

By. "composition and aggregate deposits" 1' mean deposits ofcompositions and a gregate mixtures of materials which when deposited ina wet. condition and allowed to dry will produce hard substances adaptedfor trafiic and other uses.

By "woven netting, I mean any material, the fibers or strands of whichare so loosely interwoven as to allow free passage of air and evaporatedwater therethrough, and which possesses sufiicient strength to preventthe dismemberment of the water-porous layer of material during reuse andordinary handling.

It will thus be seen that I employ an inexpensive device, capable ofre-use, for the production of improved and more uniform results at aconsiderable saving of time and expense over the present employedmethods.

I do not limit myself to the particular size, shape or arrangement ofparts specifically men- 'tioned, as these are given simply as a, meansfor clearly describing my invention.

, What I claim is:

1. A pad adapted for the curing of concrete roads consisting of anintermediate layer of loosely matted cotton and an outer layer ofloosely woven netting of jute fiber on each side of said intermediatelayer and spaced stitching for securing said intermediate and outerlayers together.

2. A pad adapted for the 'curing of concrete roads consisting of anintermediate layer of loosely matted cotton and an outer layer ofloosely woven netting of cotton fiber on each side Q of saidintermediate layer and spaced stitching {for securing said intermediateand outer layers to-

